The present invention relates to an endoscopic apparatus having an endoscope body and a drive unit which includes a video processor, light source, etc.
An endoscope may be used for the observation, treatment, or photographing of the inside of the body cavity. In doing this, the body of the endoscope is connected to a drive unit by means of a universal cord, so that the endoscope body is supplied with illumination light, electrical signals, and fluid from the drive unit. The endoscope body is connected to the drive unit by fitting a connector at the distal end of the cord into a socket of the drive unit. The connector and socket are provided with a plurality of connector units and socket units, respectively, for the light, signals, and fluid.
The connector units and socket units can be connected simultaneously by a single connecting operation. Also, electrical contacts can be securely insulated from peripheral metallic parts surrounding them, thus facilitating the prevention of electrical noise at the electrical connecting section. When connecting the connector and socket, each including a plurality of units, however, the individual units of the connector must be accurately aligned with those of the socket. Therefore, the connector and socket must be manufactured with high dimensional accuracy, thereby increasing manufacturing cost.
The maximum allowable connection/disconnection frequency of conventional electrical connectors is relatively low. According to the MIL standards, for example, it is restricted to 500 cycles or thereabout. On the other hand, the endoscope must be washed and cleaned at the end of every operation for observation or treatment, requiring very frequent connection/disconnection between the connector of the endoscope body and the socket of the drive unit. Usually, the frequency of connection/disconnection is 15 cycles a day, on average. If there are five working days per week, therefore, the frequency exceeds 3,500 cycles a year. Accordingly, the connector and socket must be not only easy to handle but also highly durable.
If both electrical and optical connecting sections are made rigid enough to fulfill the aforesaid requirement, the individual components must be manufactured with extremely high accuracy. In the optical connecting section, the quantity of light transmitted to a light guide can be reduced drastically by a slight dislocation between a light source and the incidence end of the light guide. Thus, the positional accuracy must be limited to .+-.0.5 mm in the axial direction and .+-.0.15 mm in the radial direction. In the electrical connecting section, if the respective axes of the contacts are subject to a deviation of about 0.2 mm when the connection and disconnection are repeated, the contacts will be quickly worn away. Consequently, the electrical contact resistance may be increased or contact failure may take place.
According to an endoscopic apparatus disclosed in Japanese Patent Disclosure No. 69837/82, a universal cord of an endoscope body includes two branch cords diverging in the middle from each other, and electrical and optical connector means are attached individually to the distal ends of the branch cords. In this case, the dimensional accuracy of the connector means does not matter. However, these connector means must be connected to or disconnected one by one from socket means of a drive unit, thus lowering the operating efficiency. While one connector means is being handled, moreover, the other may possibly swing, touching and damaging a panel of the drive unit.